Periodic paralyses (PPs) are rare neuromuscular disorders caused by mutations in skeletal muscle sodium, calcium, and potassium channel genes. PPs include hypokalemic paralysis, hyperkalemic paralysis, and Andersen‐Tawil syndrome. Common features of PP include autosomal dominant inheritance, onset typically in the first or second decades, episodic attacks of flaccid weakness, which are often triggered by diet or rest after exercise. Diagnosis is based on the characteristic clinic presentation then confirmed by genetic testing. In the absence of an identified genetic mutation, documented low or high potassium levels during attacks or a decrement on long exercise testing support diagnosis. The treatment approach should include both management of acute attacks and prevention of attacks. Treatments include behavioral interventions directed at avoidance of triggers, modification of potassium levels, diuretics, and carbonic anhydrase inhibitors. Muscle Nerve 57: 522–530, 2018

Objective: To determine the most critical symptoms in a national myotonic dystrophy type 1 (DM1) population and to identify the modifying factors that have the greatest effect on the severity of these symptoms. Methods:We performed a cross-sectional study of 278 adult patients with DM1 from the national registry of patients with DM1 between April and August 2010. We assessed the prevalence and relative significance of 221 critical DM1 symptoms and 14 disease themes. These symptoms and themes were chosen for evaluation based on prior interviews with patients with DM1. Responses were categorized by age, CTG repeat length, gender, and duration of symptoms.Results: Participants with DM1 provided symptom rating survey responses to address the relative frequency and importance of each DM1 symptom. The symptomatic themes with the highest prevalence in DM1 were problems with hands or arms (93.5%), fatigue (90.8%), myotonia (90.3%), and impaired sleep or daytime sleepiness (87.9%). Participants identified fatigue and limitations in mobility as the symptomatic themes that have the greatest effect on their lives. We found an association between age and the average prevalence of all themes (p Ͻ 0.01) and between CTG repeat length and the average effect of all symptomatic themes on participant lives (p Ͻ 0.01). Conclusions:There are a wide range of symptoms that significantly affect the lives of patients with DM1. These symptoms, some previously underrecognized, have varying levels of importance in the DM1 population and are nonlinearly dependent on patient age and CTG repeat length. Neurology Myotonic dystrophy type 1 (DM1) is a multisystem disorder caused by an unstable trinucleotide repeat expansion on chromosome 19q13.3 in the DMPK gene.1-3 The core features of DM1 are myotonia, weakness, and early-onset cataracts (Ͻ50 years of age). Along with these core features, patients commonly report symptoms related to cognition, gastrointestinal function, sleep, fatigue, mood, ability to swallow, vision, social relations, and physical function. 4 The effect of each symptom on health-related quality of life is unknown. Furthermore, given the multisystem manifestations of DM1, we hypothesize that there are additional underrecognized symptoms that are important to patients and have a critical effect on their health status.

Purpose of reviewMyotonic dystrophy type 1 (DM1) is a severe, progressive genetic disease that affects between 1 in 3,000 and 8,000 individuals globally. No evidence-based guideline exists to inform the care of these patients, and most do not have access to multidisciplinary care centers staffed by experienced professionals, creating a clinical care deficit.Recent findingsThe Myotonic Dystrophy Foundation (MDF) recruited 66 international clinicians experienced in DM1 patient care to develop consensus-based care recommendations. MDF created a 2-step methodology for the project using elements of the Single Text Procedure and the Nominal Group Technique. The process generated a 4-page Quick Reference Guide and a comprehensive, 55-page document that provides clinical care recommendations for 19 discrete body systems and/or care considerations.SummaryThe resulting recommendations are intended to help standardize and elevate care for this patient population and reduce variability in clinical trial and study environments.

ertilization and early embryogenesis involve the transition from specialized unipotent gametes to totipotent embryos. After fertilization, mammalian embryos rely on maternally deposited RNA but subsequently initiate ZGA during which embryonic transcription begins 1 . Diverse mechanisms control the timing of ZGA, such as controlling RNA polymerase activity, the nuclear/ cytoplasmic ratio, or translation of critical ZGA transcription factors (TFs) in Caenorhabditis elegans, Drosophila melanogaster or Danio rerio, respectively 1 . Currently, we have an incomplete understanding of how the transcriptional machinery (RNA polymerases) and/or sequence-specific TFs dictate the timing of ZGA in mammals and contribute to developmental potential.Recent work identified the TF DUX (DUX4 in humans) as a key regulator of ZGA gene expression 2-5 . When ectopically expressed in cells, DUX and DUX4 activate many ZGA genes, including the earliest wave of ZGA genes in humans and mice 2,3 . However, the extent to which DUX is required for appropriate ZGA is unclear, as the reported effect of genetic loss of Dux ranges from minor molecular to major transcriptional defects and decreased development in mouse or human embryos 4-6 .To study ZGA using a cellular model, we and others have used 2C-embryo-like cells (2CLCs), which are an endogenously fluctuating subpopulation of mouse embryonic stem cells (mESCs) that recapitulate several key features of ZGA 7 . The 2CLCs activate transcripts characteristic of the 2C mouse embryo (including Dux,

Introduction The multitude of symptoms associated with facioscapulohumeral muscular dystrophy (FSHD) disease burden are of varying importance. The extent of these symptoms and their cumulative effect on the FSHD population is unknown. Methods We conducted interviews with adult FSHD patients to identify which symptoms have the greatest effect on their lives. Each interview was recorded, transcribed, coded, and analyzed using a qualitative framework technique, triangulation, and 3-investigator consensus approach. Results 1375 quotes were obtained through 20 patient interviews. 251 symptoms of importance were identified representing 14 themes of FSHD disease burden. Symptoms associated with mobility impairment, activity limitation, and social role limitation were most frequently mentioned by participants. Conclusions There are multiple themes and symptoms, some previously under-recognized, that play a key role in FSHD disease burden.

There are many symptomatic themes that affect the lives of adults with SMA. These themes vary in prevalence and relative importance in the adult SMA population.

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Introduction In preparation for clinical trials we examine the validity, reliability, and patient understanding of the Myotonic Dystrophy Health Index (MDHI). Methods Initially we partnered with 278 myotonic dystrophy type-1 (DM1) patients and identified the most relevant questions for the MDHI. Next, we used factor analysis, patient interviews, and test-retest reliability assessments to refine and evaluate the instrument. Lastly, we determined the capability of the MDHI to differentiate between known groups of DM1 participants. Results Questions in the final MDHI represent 17 areas of DM1 health. The internal consistency was acceptable in all subscales. The MDHI had a high test-retest reliability (ICC=0.95) and differentiated between DM1 patient groups with different disease severities. Conclusion Initial evaluation of the MDHI provides evidence that it is valid and reliable as an outcome measure for assessing patient-reported health. These results suggest that important aspects of DM1 health may be effectively measured using the MDHI.